HIRN, ḗrn, Gustave Adolphe (1815-90). A French physicist, born at Logelbach, near Colmar. When he was nineteen he entered his grandfather's cotton factory as chemist; afterwards he acted as engineer, and began his valuable researches on mechanics, and especially on calorics. He was made a member of the French Academy of Science in 1867; in 1880 founded a meteorological observatory near Colmar; and later devoted himself to astronomy. Hirn was educated in the shop, and his works are marked by much practical criticism of mere academic theory. They include: Theorie mecanique de lachaleur (3d ed. 1875-76); Analyse de l'univers (1869); Mémoire sur les anneaux de Saturne (1872); Les paradynamometres (1870); Étudesur une classe particuliere de tourbillons (1878); Recherches experimentales sur les relations entrela resistance de l'air et sa temperature (1882); La vie future et la science moderne (1882); and Constitution de l'espace celeste (1889).